Over the next couple of years, we're going to build him a moped!
The goal is to get it done by the time he's old enough for a license.

I found an old Bing on eBay, which we cleaned up and bought some new parts for.

And we've taken apart an old E50 engine. Several parts are damaged or missing, so we'll be replacing them.

I'm not sure what to make of this dust pattern on the cylinder wall. The wall is smooth to the touch, and it doesn't seem to be real dust. It has a couple of scores on the wall, so I'll probably not be reusing it anyway. But it is a curiosity.

Great project. The cylinder pitting I've seen before in aluminum cylinders and they still had good compression. If the scores don't catch your fingernail, they are probably not too severe. Those cases shined up nice.

Of the two cylinders I had, I chose the one with the fewest scores and cleanest-looking walls. The old piston has already been cleaned up and fitted with new rings, so we just needed to de-glaze the cylinder wall a bit.

This cylinder had one really shallow score, and a mirror-like smoothness. Last time I used it with the new rings it was getting around 94 psi compression.

I managed to get the desired cross-hatch pattern with a small honing tool.

We got the case and cover pieces painted and cured.

With everything back together, another compression test yielded 110 psi. Can't wait to see how it performs with the new bearings and seals.

Another freewheel rebuild. This one would NOT come off the rim. Clamped the tools down nice and tight, and even my son and I both twisting as hard as we could, the thing would not budge.Penetrating oil, heat, and brute force were all futile. So this one got rebuilt on the rim.

Works great now. We managed not to lose any bearings. Although, one got sheared in half somehow, so that one got replaced.Now off to the hardware store to get some assorted nuts, bolts, and washers.

Finally getting back to this project.The engine quit on us, yesterday and I've been trying to figure out the problem. It runs fine with a little starter fluid, but I can't seem to get any gas to it. Comes out the fuel valve ok, so its gotta be the carb I suppose. Doesn't really look any different yet from last time, so I'll add pictures when more stuff gets done.